As technologies advance and the market becomes mature, smart devices per capita increase continuously, and the number of smart devices coexisting in an environment also grows constantly, where the smart devices include: mobile devices, wearable devices, smart home devices, Machine Type Communication (MTC) devices, and the like. Devices such as a wearable device and an MTC device generally need to transmit only a small amount of data at a relatively low frequency in application, and therefore, generally have a small size and a low battery capacity that limits a continuous working time after the device is charged once. Users hope to extend a battery use time of the wearable device and the MTC device as much as possible, to avoid the inconvenience of charging frequently, especially when there are a large number of devices.